Motion detection apparatus and entertainment system having a pulse counting unit

Abstract

There are provided an infrared light emitting diode 42 operable to emit light in a predetermined cycle; a phototransistor 44 operable to receive light which is emitted by the infrared light emitting diode 42 and reflected from a retroreflective sheet 40 of the operation article 3 , and output a light reception signal “Sp”; and a highpass filter unit 116 operable to pass a high frequency component of the light reception signal “Sp”, output the high frequency component as a light reception signal “Ss” and operable to generate a reference voltage. The highpass filter unit 116 supplies the reference voltage to a node to which the light reception signal “Ss” is output, and the processor 110 counts the number of pulses included in the light reception signal “Ss”, and calculates the speed of the operation article 3.

1. A motion detection apparatus operable to detect a motion of an operation article when the operation article is held and given motion by an operator, the motion detection apparatus comprising:
 a light emitting unit operable to emit light in a predetermined cycle; 
 a light receiving unit operable to receive light which is emitted by said light emitting unit and reflected from the operation article, and output a first light reception signal; and 
 a counting unit operable to receive the first light reception signal and count the number of pulses included in the first light reception signal. 
 
   
   
     2. The motion detection apparatus as claimed in  claim 1  further comprising:
 a light emitting range regulation unit operable to regulate the light emitting range of the light emitted by said light emitting unit; and 
 a light receiving range regulation unit operable to regulate the light receiving range of said light receiving unit. 
 
   
   
     3. The motion detection apparatus as claimed in  claim 1  further comprising:
 a highpass filter operable to pass a high frequency component of the first light reception signal and output the high frequency component as a second light reception signal; and 
 a reference voltage generation unit operable to generate a reference voltage, wherein 
 said reference voltage generation unit supplies the reference voltage to a node to which the second light reception signal is output, and wherein 
 said counting unit counts the number of pulses included in the second light reception signal. 
 
   
   
     4. The motion detection apparatus as claimed in  claim 2  further comprising:
 a highpass filter operable to pass a high frequency component of the first light reception signal and output the high frequency component as a second light reception signal; and 
 a reference voltage generation unit operable to generate a reference voltage, wherein 
 said reference voltage generation unit supplies the reference voltage to a node to which the second light reception signal is output, and wherein 
 said counting unit counts the number of pulses included in the second light reception signal. 
 
   
   
     5. The motion detection apparatus as claimed in  claim 3  wherein
 said reference voltage generation unit is formed by connecting a first resistor element and a second resistor element in series between a first line for supplying a first voltage and a second line for supplying a second voltage, wherein 
 said highpass filter is formed of a capacitor and the second resistor element, and wherein 
 the connection point between the first resistor element and the second resistor element is the node to which the second light reception signal is output. 
 
   
   
     6. The motion detection apparatus as claimed in  claim 3  wherein
 said reference voltage generation unit is formed by connecting a first resistor element and a second resistor element in series between a first line for supplying a first voltage and a second line for supplying a second voltage, wherein 
 said highpass filter is formed of a capacitor and the second resistor element, and wherein 
 the connection point between the first resistor element and the second resistor element is the node to which the second light reception signal is output. 
 
   
   
     7. The motion detection apparatus as claimed in  claim 1  wherein
 a single light emitting diode is used as said light emitting unit, and wherein 
 a single phototransistor is used as said light receiving unit. 
 
   
   
     8. The motion detection apparatus as claimed in  claim 2  wherein
 a single light emitting diode is used as said light emitting unit, and wherein 
 a single phototransistor is used as said light receiving unit. 
 
   
   
     9. The motion detection apparatus as claimed in  claim 3  wherein
 a single light emitting diode is used as said light emitting unit, and wherein 
 a single phototransistor is used as said light receiving unit. 
 
   
   
     10. The motion detection apparatus as claimed in  claim 4  wherein
 a single light emitting diode is used as said light emitting unit, and wherein 
 a single phototransistor is used as said light receiving unit. 
 
   
   
     11. The motion detection apparatus as claimed in  claim 5  wherein
 a single light emitting diode is used as said light emitting unit, and wherein 
 a single phototransistor is used as said light receiving unit. 
 
   
   
     12. The motion detection apparatus as claimed in  claim 6  wherein
 a single light emitting diode is used as said light emitting unit, and wherein 
 a single phototransistor is used as said light receiving unit.